This research examines preschool children's short term memory for speech. The goal is to investigate two basic processes in preschool children about which little is known: (a) the decay over time of memory for speech, and (b) the interference with memory for speech caused by subsequent input to the child. Because areas of the cortex subserving spoken language reception undergo substantial maturation in the preschool years, the related properties of memory may change. Memory for speech frequently has been explored in adults, but the techniques that have been used are not directly applicable to young children. Therefore, in the present proposal, three paradigms are developed in order to examine young children's memory for speech. One, a same-different, discrimination procedure, will be used to examine memory decay. A second paradigm makes use of rhymes to examine modalityspecific aspects of children's memory for spoken words. These experiments will examine memory decay as well as interference between words. In a third paradigm, children's ability to remember words is examined in the presence of various sentence-like interfering stimuli. Thus, the plan is to assess the most basic properties of children's memory for speech, and then to examine these properties of memory within realistic language-learning situations. The theoretical impact of the research is that, together with knowledge of brain maturation, it will contribute to an understanding of brain-behavior correspondences. Moreover, because preschool children are much less likely than adults to use retention strategies such as rehearsal, the research should provide information about basic structural as opposed to strategic properties of memory. It therefore should contribute to a general understanding of cognitive processes as well as development. The proposed research should also be of considerable practical importance, both because it would lead toward an improvement in the format of verbal instruction s to children, and because memory for speech is frequently impaired within many disorders of language.